Myself and Rantor ALWAYS carry link chains in our vehicles but I can not remember a time that we have had to put them on except in conditions that we were off the beaten track. However, with that said, we also carry a shovel, cold weather gear, extra weight in the back for traction and our vehicles are set up for getting through DEEP snow (winches, snatch blocks etc...).

I have seen and heard of I-70 in Colorado being closed to vehicles unless they are 4 wheel drive or have chains. Now with that said, refer to the post above that said to have chains / cable for all four wheels. This is a pretty important piece of advice. Because if you only have chains for the back of your truck you will get it moving - that part is the fun part! The not so fun part is if you didnt chain your FRONT wheels. These are the wheels that are important to keep from sliding so they will allow you to turn and stop! Stop power is much more important to me then go power.

Just my 2 cents...
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A government big enough to give you everything you want,
is strong enough to take everything you have.
Thomas Jefferson